Purpose: The purpose of this paper is to assess the impact of Literacy Boost Project Model implemented by World Vision on reading skills of early grade students in Ethiopia. It intended to examine whether the intervention contributed to improving students' achievement in reading comprehension. Design/methodology/approach: Difference in difference with propensity score matching impact estimation model was used in the study. Baseline and end line data collected by World Vision Ethiopia in four districts in Oromia region, where the project had been operational, were used for the research. A total of 1,418 students (685 control and 733 intervention) were selected using random sampling technique and assessed based on the core reading skill components. Findings: The result of the analysis indicated significant improvement in the core reading skills of treated students. The ultimate outcome of reading comprehension skill from the previous evaluation was found inflated. Variables related to the home literacy environment and community activities were found significantly impacting the students reading achievement. Research limitations/implications: Policies and strategies intended to improve the quality of education, particularly the reading skills of early grade students, in the study area and scaling up the literacy boost project to areas with similar context, thus should give due attention to the variables related to the home literacy environment and community activities. Originality/value: This study is important in providing valuable information on early grade education quality improvement interventions, especially to development practitioners and policymakers to make informed decisions regarding education sector reform and development in the study area.